The present invention relates to flexible tubular pipes for transporting hydrocarbons.
It relates more precisely to a pipe of the type described in the standardized documents published by the American Petroleum Institute (API) and especially documents API 17J and API RP 17B.
This type of pipe comprises successive layers that are independent of one another consisting, on the one hand, of helical windings, of tapes and/or of profiled wires and, on the other hand, of at least one sheath made of polymer material. Whereas the metal layers have the function of taking up the mechanical forces, both internal and external, the polymer sheaths have the function of providing internal or external sealing.
The various layers are to a certain extent movable one with respect to another so as to allow the pipe to bend. Various structures exist for such pipes, however they all generally have a multilayer assembly called a pressure vault, intended to take up the radial forces, and a multilayer assembly intended to take up the axial forces.
Usually, the pressure vault located on the inside of the pipe consists of a short-pitch helical winding of a profiled wire, and the layers intended to take up the axial forces, located on the outside of the pipe, generally consist of a pair of armor plies consisting of crossed wires wound helically with a long pitch.